- improve snake using Claude 3.7 + Extended

- completely redesign UI with responsive layout and dark mode support
- add game states (start, pause, game over screens)
- implement new game modes (classic, no-walls, powerups)
- add special food and powerup system (speed, invincibility, points)
- introduce achievement system with localStorage persistence
- improve collision detection and random position generation
- add mobile-friendly controls with touch swipe support
- create visual effects (animations, points popup)
- implement proper game timer and level progression
- replace Hammer.js dependency with vanilla JS for touch events

Prompt:
```
<goal>
As you can see, the attached game is not very sophisticated yet, but the core functionality is working well.
Our goal is to improve it thoroughly.
</goal>
<requirements>
* Don't overengineer.  Add smart, simple and straightforward features.
* Don't change the core functionality.
* The game should stay in the scope of this single HTML page.
* Provide the updated code with a minimal amount of line breaks and indentations in order to save tokens.
* Implement modern, well-structured and fitting design, UI and UX.
* Add gameplay features that will increase the fun-potential.
* Think thoroughly before presenting your final implementation.
</requirements>
<task>
Raise the quality of this standalone page to a highly sophisticated and professional level and provide the updated code.
</task>
```

Needed another two prompts to fix some bugs and improve the UI.

Author: TobiasMue91